Variable-cut-off valve mechanism.



F. L. PRESCUTT. VARIABLE can-UFF VALVE ME (HANISM.

APPLICATION FHED IULY 24.

Patented May 14, 1918.

2 SHEETS-SHEET l F. L. PRESCOU.

VARIABLE CUT-OFF VALVE MECHANISM. APPLICATION min lun 24.1917.

1 ,266, 046. Patented Mayl4, 1918.

2 SHEETS-SHEET 2.

r the period during which the FORI) L. FRESCO BTT, 0F ELMIRA, NEW YORK.

VARIABLE@ iT-OFF VALVE MECHANISM.

Specification of Letters Patent.

Patented May 14, 1918.

Application 111er;i July 24, 1917. Serial No. 182,5

To all 'whom it may concern.'

Be it known that I, Fono L. Pnesvofm, a. citizen of the United States, residing at Elmira, in the county of Chemung and State of New York, have invented certain new and useful Improvements in VariableCut` Off Valve Mechanism; and I do hereby declare the following to be a full, clear, and exact description of the invention, such' as will enable others skilled in the art f'o which it appertains to make and use the same.

This` invention relates to engines and more particularly to the: valve mechanism thereof. It is one of the objects of the resent invention to improve the design o the construction of tho combustion chamber of internal combustion motors to facilitate the ignition of a charge of fuel therein. Tff that end the details of the present invention reside in the improvements in desi and location of the combustion or spar ng chamber of a motor whereby the fuel to be ignited is concentrated in a. space immediately about the spark plugr and whereby the spreading of the fuel to be ignited throughout the en ine head is eliminated. The advantage of this feature of the invention is that the ignited fuel is more perfectly and rapidly burned with a material economy in the consumption of the amount of fuel required in the operation of the engine. Another object of Y the valve gear thereof for more eiectually controlling the u ose of thepleliipg'th of intake and exthe combustion and it is also in this respect, an object of the invention to improve the construction of the valve members so that they may be made of relatively small size when compared to the size of a. given motor, and which also permits of the integral construction of the cylinder and cyiinder head thereby eliminating separable parts and avoiding the formation of joints and also doing away with the usual means employed to fasten separable parts when the engine body comprises a separate cylinder and head for each unit of its motor.4 A further and important object of the present iuvention is the provision oi' a valve graiwhich is readily adjustable to vary the pe'- riod of the opening of the intake and ein liaust ports so as to make the e 'ne open able more eilicicntly under varying oads and verving speeds, and further, it 1s an object naast passageways from chamber are opened,

of the present invention to provide a valve structure of such type whereby it ma be utilized as an element deriving power rom. the exploded gases in the combustion chainber to help or assist in the driving of the crank shaft of the motor and thereby .improve the operation of the engine in such manner that there is a nearly constant torque throughout the operation of the engine over a wide variation in the speed range and with a resultant elioiency in consumption of fuel ai: high and low speed. To that end one feature of my present invention resides in thc formation of a valve gear including relatively slidable members one of which may be designed as a piston for utilizing power derived from the force of exploding gases to assist in the driving of the crank shaft of the motor and includes means for relatively adjusting the valve members so as to control the length of pcriod of the opening of the exhaust and inlet ports of the engine casing.

' With the above and other objects in view as will be rendered manifest in the following specification and which will be readily apparent to those skilled in the art,`my invention consists in the construction, combination and arrangement of the parts as described in the following specilication and illustrated in the accompanying drawings, wherein one embodiment of the invention is disclosed.

In the drawings:

Figure 1 is a central transverse section through a portion of the motor cylinder and the improved valve gear;

Fig. 2 is a detail sectional view of the valve operating mechanism;

Fig. .3 is a detail sectional View of the upper portion of the cylinder showing the valve in the intake position;

Fig. 4- is a similar view showing the valve in the exhaust position; and

Fig. 5 is a diagrammatic view of the variable .valve action.

It is well known that in n.11 types of internal combustion engines in which the eriod of opening of the several ports remains constant throughout the operation 'of the engine, indcpendentl of the load the engine has to carry andy independently also of the various rates oflspeed` with which the engine is called upoh'tb operate, that there is a material loss ofpriwerbecause of this constancy of the optiilperiod of the ports increasing the power derived from t e fuel lli and a serious loss of fuel for the same reason. While my present in view several ob]ects for the pu ose of during the running of the en 'ne and for the purpose also of simplifying the construction of the engine and thereby reducing the cost of the manufacture of the several parts thereof, one of the more important objects of my present invention is to rovide means `hereby the period of opening of the inta, :e and exhaust ports may be varied as found requisite by conditions occurring in the operation of motors of this character. While the broad idea of varyingl he period of opening of the inlet and ex eist ports may be incorporated in several forms of valves and valve gears I have elected in the present instance to isclose such a valve gear as comprising relatively slidable parts, each opera by a suitable mechanism, these being provided for the relative adjustments of the positions 'of the parts of the valve to one another to secure the desired period of opening during the various operating conditions of the motor. o

Therefore, I have shown the invention as incorporated in an engine one cylinder of which is indicated at 2 within which there is operable a piston nprovided with a coi necting rod 4 for connection to the usual crank shaft in any. suitable and` well known manner. As one object of my invention is to improve the method of producing combustion of the fuel vapors in the combustion chamber, I have shown the u per end of the piston 3 as rounded and w en this latter 1s in the upper position as shown it comes close to the head 5 of the c linder so as to displace gases therein an cause the compression of the gases in one stroke of tlfe piston 3 in a substantially spherical chamber 6 shown as eccentrica ly located with relation to the chamber of the cylinder 2, and provided with a spark plug 7.

- eccentric 12, this latter naled in the casing of the en The valve gear hereinbefore referred to comprises a piston 8 having a concaved head 9 forming one side of the combustionlcham'- ber 6, the piston operating in a chamber 10 formed lateral to and parallel with the cylinder 2, and provided at its lower end with a wrist 'pin 11 which is mounted in an having a wlownwardly extending arm 13 connected `at 14 to a hnk 15 which in turn is connected at 16 to the upper en Y, of a crank` arm 17 fastened on a rock shaft 18 suitably )oure. Interposed between the piston 8 an the bore of the cylinder 10 there is provided a sleeve valve 20 of smewhat greater length than the piston 8 and having at its upper end an exterior wide packing. member 21 so disposed that when in its lowermost position invention has position shown in Fig. 1 and .moving downwardly together,

. tive ports is satisfactory it, will cover an inlet port, 22 formed in the upper portion of the valve cylinder 10. The sleeve valve 20 is also provided at a point just below the band 21 with an annular-port 23 of suitable length and width adapted to open when in its lowermost position with the exhaust port 24. Obviously the piston 8 is provided with exterior packing rin 8 the upper of which is adapted to over ap the exhaust port 23 of the valve sleeve 20 when the parts are in the osition shown in Fig. 1. To impart relative slidin movement to the valve piston and the va ve sleeve as .to the casin of the engine, the piston 8 is connected lay means of a connecting rod 26 to an eccentric portion 27 of a one-half speed shaft 28 suitably geared to the crank shaft of the motor, the upper end of the connecting rod 26 bearing upon the eccentric bushing 12 above referre to as mounted on the wrlsepin 11, and the valve sleeve 20 is connec at 29 Fi 2 to a link 30 connected at its lower en to an eccentric portion 31 of the valve shaft 28. The relative angular positiolft of the eccentric portions 27 and 31 of the crank shaft 28 is such that the piston 8 is moved relative to the valve sleeve 20 to open the ort 23 of the valve sleeve when the latter 1s in such osition that its port registers with the in et or the exhaust port of the motor casing clearly shown in Figs. 3 and .4, while when the sleeve valve 20 is in the the parts are the piston 8 ctivers the port 23 of thepiston sleeve 20.

As shown in the diagrammatic view, Fig. 5, it will be seen, by the full line position of the top of the piston and the sleeve port when the valve members are set in one position with respect to the crank shaft, angular positions of which are designated by the numerals beginning 0 (zero) extending to 630, that the exhaust port may be maintained in an o en position for a period of 240 while the inlet port may be maintained in open position for a followin eriod of 220. This period of openin o t e r ecan eiiicient w ile the engine is operating at high speed where the inertia of the fuel and' exhaust gases has a tendency to aid a power piston during the suction and the eduction strokes, but at low speed the velocity of the gas is much less and this condition of the timin of the valve is ineilicient because of a ten ency of a return surgie` ofthe 4 ases before the valve is closed. his resu ts in a loss of owerA and an extrava ant consumption of el as a portion of t e fuel charge is caused to be thrown back through the earbureter. From this it will be seen that by my arrangement of valve and through the provision of therock shaft -the piston valve can be moved relatively to the lsleeve valvel aecomo as shown by the dotted line in Fig. 5 to impart power from the combustion cham- 50 so as to materially reduce the period of ber to the crank shaft and a sleeve valve opening of the intake a's shown in the diaembracing about the piston valve, and gram to an extent of 200 for the exhaust means for operating said valves whereby and 185 for the inlet which is suitable for the exhaust is opened at the lower limit of the operation of the engine at low s eed. movement of the piston valve whereby the While I prefer to turn the valve sha t 28 lower halil of the downstroke of the piston yin the direction of the arrow in Fig. 1 so valve is utilized to transmit power to the -that the advantage of the pressure of the main shaft ef the engine.

` would remain constant.

expanding gases on the iston 8 is utilized 4. In an internaly combustion engine, a to assist the crank sha t, it is understood casing having a piston cylinder and respecof co rse, that the valve shaft may operate tively upper and lower intake and outlet in eit er direction asy may be desired. ports, and a valve organization operative to It is further understood that in cases vary the opened and closed periods olf the where the speeds and loads do not vary ports to the cylinder and including a ported greatly, the variable feature may be omit sleeve and a istontherein uncovering the 66 ted, in which case all the other vparte would exhaust and s eeve port when in its lowerbe substantially as shown, but in which most osition. the duration of inlet and exhaust periods 5. n an internal combustion engine having a casing with a iston cylinder with la What is claimed as new iszlateral combustion *chamber having intake 70 1. In an internal combustion engine 'a and outlet ports, a valve organization in cylinder and its piston, a lateral explosion said chamber comprising relatively adjustchamber having adjacent inlet and outlet able, coperative concentric iston and sleeve ports for the cylinder, a sleeve valve intervalve members controlling flbw at said ports, posed between said ports and the cylinder said sleeve having a `circumferential port 76 and having a port coordinate with said registrable with said ports, said piston operu ports; a iston valve o eratively fitting the Y ative to cover and uncover the port. sleeve va ve for control ing iow through the 6. In an internal combustion engine a casvalve port, a crank shaft connected to said ing with a main piston cylinder and intake valve and means for adjusting the piston and' outlet ports therefor, a valve or aniza 80 valve independently of the sleeve valve. tion comprising relatively adjustab e, c0-

2. In an internal combustion engine, a operative concentric piston and sleeve valve casing having a piston cylinder and a commembers controlln flow at said ports, and

bustion chamber disposed laterally thereto means for relative y adjusting said piston and having axially alined and adjacent inat will to vary the open periods of both the let and outlet ports, a sleeve valve havin inlet and exhaust ports.l a port alternately? registrable with saig 7. In an internal combustion engine a ports, a piston valve in said sleeve to cover casing with a piston cylinder having a lat the port thereof7 a crank shaft with a crank eral combustion chamber with intake and for each valve member, a connectin pitoutlet ports, a valve organization in said man for the piston valve and its orang, and chamber comprising relatively ad'ustable, an adjustable connection between said pitcooperative 'concentric 'piston an sleeve man and the valve whereby the operating valve members controlling How at said ports, cycle of the piston is variable as -tothe means for relatively adjusting said members sleeve. at will, and meansfor actu'ating said mem- 95 3. In an internal combustion engine, a bers independently of the adjusting means. valve organization including a piston valve In testimony whereof I aHix mg signature. enacting with the usual piston of the motor FORD L. PR SCOTT. 

